CXCL1 gene silencing in skin using liposome-encapsulated siRNA delivered by microprojection array

3D-Printed Latticed Microneedle Array Patches for Tunable and Versatile Intradermal Delivery

Using high-resolution 3D printing, a novel class of microneedle array patches (MAPs) is introduced, called latticed MAPs (L-MAPs). Unlike most MAPs which are composed of either solid structures or hollow needles, L-MAPs incorporate tapered struts that form hollow cells capable of trapping liquid droplets. The lattice structures can also be coated with traditional viscous coating formulations, enabling both liquid- and solid-state cargo delivery, on a single patch. Here, a library of 43 L-MAP designs is generated and in-silico modeling is used to down-select optimal geometries for further characterization. Compared to traditionally molded and solid-coated MAPs, L-MAPs can load more cargo with fewer needles per patch, enhancing cargo loading and drug delivery capabilities. Further, L-MAP cargo release kinetics into the skin can be tuned based on formulation and needle geometry. In this work, the utility of L-MAPs as a platform is demonstrated for the delivery of small molecules, mRNA lipid nanoparticles, and solid-state ovalbumin protein. In addition, the production of programmable L-MAPs is demonstrated with tunable cargo release profiles, enabled by combining needle geometries on a single patch.

Nanotechnology strategies to address challenges in topical and cellular delivery of siRNAs in skin disease therapy

Gene therapy is one of the most advanced therapies in current medicine. In particular, interference RNA-based therapy by small interfering RNA (siRNA) has gained attention in recent years as it is a highly versatile, selective and specific therapy. In dermatological conditions, topical delivery of siRNA offers numerous therapeutic advantages, mainly by inhibiting the expression of target transcripts directly in the skin. However, crossing the stratum corneum and overcoming intracellular barriers is an inherent challenge. Substantial efforts by scientists have moved towards the use of multimodal and multifunctional nanoparticles to overcome these barriers and achieve greater bioavailability in their site of action, the cytoplasm. In this review the most innovative strategies based on nanoparticle and physical methods are presented, as well as the design principles and the main factors that contribute to the performance of these systems. This review also highlights the synergistic contributions of medicine, nanotechnology, and molecular biology to advancing translational research into siRNA-based therapeutics for skin diseases.

Osmani R, Hani U, Yoonus Thajudeen K, Kiran Raj G, Gowda DV. Recent advances in the liposomal nanovesicles based immunotherapy in the treatment of cancer: A review

Immunotherapy, along with chemotherapy, targeted delivery, radiation and surgery has become one of the most common cancer treatments. The aim of cancer immunology is to use the bodys immune system to combat tumors and develop a robust antitumor immune response. In the last few years, immune checkpoint inhibitors and chimeric antigen receptor-modified T cells have made substantial advancements in cancer immunotherapy. By boosting cell type-specific delivery and immunological responses, nanocarriers like liposomes have the ability to enhance greater immune responses. The efficacy of anti-tumor therapeutics is being significantly improved as liposomes can assist in resolving a number of issues that can arise from a variety of cancer immunotherapies. Since, liposomes can be loaded with both hydrophilic and hydrophobic drugs and protect the immunotherapeutic agents loaded inside the core, they offer significant advantages over other nano delivery systems. The use of liposomes for accurate and timely delivery of immunotherapies to particular targeted neoplasms, with little or no injury to healthy cells, maximizes immunotherapy efficacy. Liposomes are also suitable vehicles for delivering medications simultaneously with other therapies such as chemotherapy, radiation, and phototherapy. Liposomal nanoparticles will be introduced and used as an objective immunotherapy delivery system for great precision, making them a viable cancer treatment approach.With an emphasis on dendritic cells, T cells, tumor and natural killer cells, and macrophages; outline of many forms of immune-therapies in oncology and cutting-edge advances in liposomal nanovesicles for cancer immunotherapy are covered in this review.

Polymeric microneedles for enhanced drug delivery in cancer therapy

Microneedles (MNs) have attracted the interest of researchers. Polymeric MNs offer tremendous promise as drug delivery vehicles for bio-applications because of their high loading capacity, strong patient adherence, excellent biodegradability and biocompatibility, low toxicity, and extremely cheap cost. Incorporating enhanced-property nanomaterials into polymeric MNs matrix increases their features such as better mechanical strength, sustained drug delivery, lower toxicity, and higher therapeutic effects, therefore considerably increasing their biomedical application. This paper discusses polymeric MN fabrication techniques and the present status of polymeric MNs as a delivery method for enhanced drug delivery in cancer therapeutic applications. Furthermore, the opportunities and challenges of polymeric MNs for improved drug delivery in cancer therapy are highlighted.

Microneedle systems for delivering nucleic acid drugs

Background

Nucleic acid-based gene therapy is a promising technology that has been used in various applications such as novel vaccination platforms for infectious/cancer diseases and cellular reprogramming because of its fast, specific, and effective properties. Despite its potential, the parenteral nucleic acid drug formulation exhibits instability and low efficacy due to various barriers, such as stability concerns related to its liquid state formulation, skin barriers, and endogenous nuclease degradation. As promising alternatives, many attempts have been made to perform nucleic acid delivery using a microneedle system. With its minimal invasiveness, microneedle can deliver nucleic acid drugs with enhanced efficacy and improved stability.

Area covered

This review describes nucleic acid medicines' current state and features and their delivery systems utilizing non-viral vectors and physical delivery systems. In addition, different types of microneedle delivery systems and their properties are briefly reviewed. Furthermore, recent advances of microneedle-based nucleic acid drugs, including featured vaccination applications, are described.

Expert opinion

Nucleic acid drugs have shown significant potential beyond the limitation of conventional small molecules, and the current COVID-19 pandemic highlights the importance of nucleic acid therapies as a novel vaccination platform. Microneedle-mediated nucleic acid drug delivery is a potential platform for less invasive nucleic acid drug delivery. Microneedle system can show enhanced efficacy, stability, and improved patient convenience through self-administration with less pain.

Microneedle Arrays Combined with Nanomedicine Approaches for Transdermal Delivery of Therapeutics

Organic and inorganic nanoparticles (NPs) have shown promising outcomes in transdermal drug delivery. NPs can not only enhance the skin penetration of small/biomacromolecule therapeutic agents but can also impart control over drug release or target impaired tissue. Thanks to their unique optical, photothermal, and superparamagnetic features, NPs have been also utilized for the treatment of skin disorders, imaging, and biosensing applications. Despite the widespread transdermal applications of NPs, their delivery across the stratum corneum, which is the main skin barrier, has remained challenging. Microneedle array (MN) technology has recently revealed promising outcomes in the delivery of various formulations, especially NPs to deliver both hydrophilic and hydrophobic therapeutic agents. The present work reviews the advancements in the application of MNs and NPs for an effective transdermal delivery of a wide range of therapeutics in cancer chemotherapy and immunotherapy, photothermal and photodynamic therapy, peptide/protein vaccination, and the gene therapy of various diseases. In addition, this paper provides an overall insight on MNs' challenges and summarizes the recent achievements in clinical trials with future outlooks on the transdermal delivery of a wide range of nanomedicines.

Advanced Medical Therapies in the Management of Non-Scarring Alopecia: Areata and Androgenic Alopecia

Alopecia is a challenging condition for both physicians and patients. Several topical, intralesional, oral, and surgical treatments have been developed in recent decades, but some of those therapies only provide partial improvement. Advanced medical therapies are medical products based on genes, cells, and/or tissue engineering products that have properties in regenerating, repairing, or replacing human tissue. In recent years, numerous applications have been described for advanced medical therapies. With this background, those therapies may have a role in the treatment of various types of alopecia such as alopecia areata and androgenic alopecia. The aim of this review is to provide dermatologists an overview of the different advanced medical therapies that have been applied in the treatment of alopecia, by reviewing clinical and basic research studies as well as ongoing clinical trials.

Progress and perspective of microneedle system for anti-cancer drug delivery

Transdermal drug delivery exhibited encouraging prospects, especially through superficial drug administration routes. However, only a few limited lipophilic drug molecules could cross the skin barrier, those are with low molecular weight and rational Log P value. Microneedles (MNs) can overcome these limitations to deliver numerous drugs into the dermal layer by piercing the outermost skin layer of the body. In the case of superficial cancer treatments, topical drug administration faces severely low transfer efficiency, and systemic treatments are always associated with side effects and premature drug degradation. MN-based systems have achieved excellent technical capabilities and been tested for pre-clinical chemotherapy, photothermal therapy, photodynamic therapy, and immunotherapy. In this review, we will focus on the features, progress, and opportunities of MNs in the anticancer drug delivery system. Then, we will discuss the strategies and advantages in these works and summarize challenges, perspectives, and translational potential for future applications.

Upconversion Nanoparticle Powered Microneedle Patches for Transdermal Delivery of siRNA

Microneedles (MNs) permit the delivery of nucleic acids like small interfering RNA (siRNA) through the stratum corneum and subsequently into the skin tissue. However, skin penetration is only the first step in successful implementation of siRNA therapy. These delivered siRNAs need to be resistant to enzymatic degradation, enter target cells, and escape the endosome-lysosome degradation axis. To address this challenge, this article introduces a nanoparticle-embedding MN system that contains a dissolvable hyaluronic acid (HA) matrix and mesoporous silica-coated upconversion nanoparticles (UCNPs@mSiO₂ ). The mesoporous silica (mSiO₂ ) shell is used to load and protect siRNA while the upconversion nanoparticle (UCNP) core allows the tracking of MN skin penetration and NP diffusion through upconversion luminescence imaging or optical coherence tomography (OCT) imaging. Once inserted into the skin, the HA matrix dissolves and UCNPs@mSiO₂ diffuse in the skin tissue before entering the cells for delivering the loaded genes. As a proof of concept, this system is used to deliver molecular beacons (MBs) and siRNA targeting transforming growth factor-beta type I receptor (TGF-βRI) that is potentially used for abnormal scar treatment.

Basic concepts, current evidence, and future potential for gene therapy in managing cutaneous wounds

OBJECTIVE

Several studies have investigated the role of gene therapy in the healing process. The aim of this review is to explain the gene delivery systems in wound area.

RESULTS

Ninety-two studies were included and comprehensively overviewed. We described the importance of viral vectors such as adenoviruses, adeno-associated viruses, and retroviruses, and conventional non-viral vectors such as naked DNA injections, liposomes, gene gun, electroporation, and nanoparticles in achieving high-level expression of genes. Application of viral transfection, liposomal vectors, and electroporation were the main gene delivery systems. Genes encoding for growth factors or cytokines have been shown to result in a better wound closure in comparison to application of the synthetic growth factors. In addition, a combination of stem cell and gene therapy has been found an effective approach in regeneration of cutaneous wounds.

CONCLUSIONS

This article gives an overview of the methods and investigations applied on gene therapy in wound healing. However, clinical investigations need to be undertaken to gain a better understanding of gene delivery technologies and their roles in stimulating wound repair.

Microneedle-Assisted Transdermal Delivery of Etanercept for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a complicated autoimmune disease. The clinical applications of etanercept (EN), a TNF-α inhibitor, can efficiently halt the development of RA. EN is mainly administrated by subcutaneous injection, which may cause low compliance, side effects, and infection risk. In this study, a hyaluronic acid crosslinked microneedle system (MN) was constructed as the transdermal alternative to deliver EN. We describe the formulation, fabrication, characterization, and transdermal insertion study of MN. In vitro bioactivity of EN was conducted and analyzed by dynamic light scattering and circular dichroism spectrum. In vivo evaluation of MN was studied on adjuvant-induced arthritis mice. The MN possessed sufficient mechanical strength, good biocompatibility, little influence on the bioactivity of EN, and high anti-inflammatory efficacy. This work represents a successful example of delivering macromolecule therapeutic treatment by MN for RA treatment. The transdermal delivery of EN by MN offers a new treatment option for RA patients.

Epidermal micro-perforation potentiates the efficacy of epicutaneous vaccination

The skin is an immune organ comprised of a large network of antigen-presenting cells such as dendritic cells, making it an attractive target for the development of new vaccines and immunotherapies. Recently, we developed a new innovative and non-invasive vaccination method without adjuvant based on epicutaneous vaccine patches on which antigen forms a dry deposit. Here we describe in mice a method for potentiating the efficacy of our epicutaneous vaccination approach using a minimally invasive and epidermis-limited skin preparation based on laser-induced micro-perforation. Our results showed that epidermal micro-perforation increased trans-epidermal water loss, resulting in an enhancement of antigen solubilization from the surface of the patch, and increased the quantity of antigen delivered to the epidermis. Importantly, this was not associated with an increase in systemic passage of the antigen. Skin micro-perforation slightly activated keratinocytes without inducing an excessive level of local inflammation. Moreover, epidermal micro-perforation improved antigen capture by epidermal dendritic cells and specifically increased the level of Langerhans cells activation. Finally, we observed that epidermal micro-perforation significantly increased the level of the specific antibody response induced by our epicutaneous Pertussis vaccine candidate containing non-adsorbed recombinant Pertussis Toxin and reduced the amount of antigen dose required. Overall, these data confirm the benefit of a minimal and controlled epidermal preparation for improving the effectiveness of an epicutaneous patch-based vaccine, without adversely affecting the safety of the method.

Individually coated microneedles for co-delivery of multiple compounds with different properties

Microneedle (MN) patches provide a simple method for delivery of drugs that might otherwise require hypodermic injection. Conventional MN patch fabrication methods typically can load only one or possibly multiple miscible agents with the same formulation on all MNs, which limits the combination and spatial distribution of drugs and formulations having different properties (such as solubility) in a single patch. In this study, we coated MNs individually instead of coating all MNs from the same formulation, making possible a patch where each individual MN is coated with different formulations and drugs. In this way, individually coated MN patches co-delivered multiple agents with different physicochemical characteristics (immiscible molecules, proteins, and nanoparticles) and in different spatial patterns in the skin. MN loading was adjusted by modifying the number of coating layers, and co-delivery of multiple agents was demonstrated in the porcine skin. We conclude that individually coating MNs enables co-delivery of multiple different compounds and formulations with needle-by-needle spatial control in the skin.

Rapid and selective sampling of IgG from skin in less than 1 min using a high surface area wearable immunoassay patch

Microprojection array (MPA) patches are an attractive approach to selectively capture circulating proteins from the skin with minimal invasiveness for diagnostics at the point-of-care or in the home. A key challenge to develop this technology is to extract sufficient quantities of specific proteins from within the skin to enable high diagnostic sensitivity within a convenient amount of time. To achieve this, we investigated the effect of MPA geometry (i.e. projection density, length and array size) on protein capture. We hypothesised that the penetrated surface area of MPAs is a major determinant of protein capture however it was not known if simultaneously increasing projection density, length and array size is possible without adversely affecting penetration and/or tolerability. We show that increasing the projection density (5000-30,000 proj. cm^-2) and array size (4-36 mm²) significantly increases biomarker capture whilst maintaining of a similar level tolerability, which supports previous literature for projection length (40-190 μm). Ultimately, we designed a high surface area MPA (30,000 proj. cm^-2, 36 mm², 140 μm) with a 4.5-fold increase in penetrated surface area compared to our standard MPA design (20,408 proj. cm^-2, 16 mm², 100 μm). The high surface area MPA captured antigen-specific IgG from mice in 30 s with 100% diagnostic sensitivity compared with 10-30 min for previous MPA immunoassay patches, which is over an order of magnitude reduction in wear time. This demonstrates for the first time that MPAs may be used for ultra-rapid (<1 min) protein capture from skin in a time competitive with standard clinical procedures like the needle and lancet, which has broad implications for minimally invasive and point-of-care diagnostics.

Intradermal delivery of STAT3 siRNA to treat melanoma via dissolving microneedles

Hyperactivity of signal transducer and activity of transcription 3 (STAT3) plays a crucial role in melanoma invasion and metastasis. Gene therapy applying siRNA targeting STAT3 is a potential therapeutic strategy for melanoma. In this article, we first fabricated safe and novel dissolving microneedles (MNs) for topical application of STAT3 siRNA to enhance the skin penetration of siRNA and used polyethylenimine (PEI, 25 kDa) as carrier to improve cellular uptake of siRNA. The results showed that MNs can effectively penetrate skin and rapidly dissolve in the skin. In vitro B16F10 cell experiments presented that STAT3 siRNA PEI complex can enhance cellular uptake and transfection of siRNA, correspondingly enhance gene silencing efficiency and inhibit tumor cells growth. In vivo experiments indicated that topical application of STAT3 siRNA PEI complex delivered by dissolving MNs into skin can effectively suppress the development of melanoma through silencing STAT3 gene, and the inhibition effect is dose-dependent. STAT3 siRNA delivery via dissolving MNs is a promising approach for skin melanoma treatment with targeting inhibition efficacy and minimal adverse effects.

Novel Approach of Using Near-Infrared Responsive PEGylated Gold Nanorod Coated Poly(l-lactide) Microneedles to Enhance the Antitumor Efficiency of Docetaxel-Loaded MPEG-PDLLA Micelles for Treating an A431 Tumor

The combination of chemotherapy and photothermal therapy (PTT) plays a significant role in synergistic tumor therapy. However, a high dosage of chemotherapy drugs or photothermal agents may cause series side effects. To overcome these challenges, we designed a near-infrared (NIR) responsive PEGylated gold nanorod (GNR-PEG) coated poly(l-lactide) microneedle (PLLA MN) system (GNR-PEG@MN) to enhance antitumor efficiency of docetaxel-loaded MPEG-PDLLA (MPEG-PDLLA-DTX) micelles for treating an A431 tumor. The as-made GNR-PEG@MNs contained only 31.83 ± 1.22 μg of GNR-PEG per patch and exhibited excellent heating efficacy both in vitro and in vivo. Meanwhile, GNR-PEG@MN with the height of 480 μm had good skin insertion ability and was harmless to the skin. On the other hand, GNR-PEG@MN had good heating transfer ability in vivo, and the tumor sites could reach 50 °C within 5 min. In comparison with chemotherapy and PTT alone, the combination of low dosage MPEG-PDLLA-DTX micelles (5 mg/kg) and GNR-PEG@MNs completely eradicated the A431 tumor without recurrence in vivo, demonstrating a remarkable synergetic effect. Hence, GNR-PEG@MN could be a promising carrier to enhance the antitumor effect of MPEG-PDLLA-DTX micelles for treating superficial tumors and is expected to have a great potential in clinical translation for human epidermoid cancer therapy.

Can gene editing and silencing technologies play a role in the treatment of head and neck cancer?

Conventional treatment strategies have done little to improve the prognosis or disease-free survival in head and neck cancer (HNC) patients. Recent progress in our understanding of molecular aspects of head and neck squamous cell carcinoma (HNSCC) has provided insights into the potential use of molecular targeted therapies in combination with current treatment strategies. Here we review the current understanding of treatment modalities for both HPV-positive and HPV-negative HNSCCs with the potential to use gene editing and silencing technologies therapeutically. The development of sequence-specific RNA interference (RNAi) with its strong gene-specific silencing ability, high target specificity, greater potency and reduced side effects, has shown it to be a promising therapeutic candidate for treating cancers. CRISPR/Cas gene editing is the newest technology with the ability to delete, mutate or replace genes of interest and has great potential for treating HNSCCs. We also discuss the major challenge in using these approaches in HNSCC; that being the choice of target and the ability to deliver the payload. Finally, we highlight the potential combination of RNAi or CRIPSR/Cas with current treatment strategies and outline the possible path to the clinic.

Development of an Innovative Intradermal siRNA Delivery System Using a Combination of a Functional Stearylated Cytoplasm-Responsive Peptide and a Tight Junction-Opening Peptide

As a new category of therapeutics for skin diseases including atopic dermatitis (AD), nucleic acids are gaining importance in the clinical setting. Intradermal administration is noninvasive and improves patients′ quality of life. However, intradermal small interfering RNA (siRNA) delivery is difficult because of two barriers encountered in the skin: intercellular lipids in the stratum corneum and tight junctions in the stratum granulosum. Tight junctions are the major barrier in AD; therefore, we focused on functional peptides to devise an intradermal siRNA delivery system for topical skin application. In this study, we examined intradermal siRNA permeability in the tape-stripped (20 times) back skin of mice or AD-like skin of auricles treated with 6-carboxyfluorescein-aminohexyl phosphoramidite (FAM)-labeled siRNA, the tight junction modulator AT1002, and the functional cytoplasm-responsive stearylated peptide STR-CH₂R₄H₂C by using confocal laser microscopy. We found that strong fluorescence was observed deep and wide in the epidermis and dermis of back skin and AD-like ears after siRNA with STR-CH₂R₄H₂C and AT1002 treatment. After 10 h from administration, brightness of FAM-siRNA was significantly higher for STR-CH₂R₄H₂C + AT1002, compared to other groups. In addition, we confirmed the nontoxicity of STR-CH₂R₄H₂C as a siRNA carrier using PAM212 cells. Thus, our results demonstrate the applicability of the combination of STR-CH₂R₄H₂C and AT1002 for effective intradermal siRNA delivery.

Transdermal Delivery of siRNA through Microneedle Array

Successful development of siRNA therapies has significant potential for the treatment of skin conditions (alopecia, allergic skin diseases, hyperpigmentation, psoriasis, skin cancer, pachyonychia congenital) caused by aberrant gene expression. Although hypodermic needles can be used to effectively deliver siRNA through the stratum corneum, the major challenge is that this approach is painful and the effects are restricted to the injection site. Microneedle arrays may represent a better way to deliver siRNAs across the stratum corneum. In this study, we evaluated for the first time the ability of the solid silicon microneedle array for punching holes to deliver cholesterol-modified housekeeping gene (Gapdh) siRNA to the mouse ear skin. Treating the ear with microneedles showed permeation of siRNA in the skin and could reduce Gapdh gene expression up to 66% in the skin without accumulation in the major organs. The results showed that microneedle arrays could effectively deliver siRNA to relevant regions of the skin noninvasively.

Topical Anti-Nuclear Factor-Kappa B Small Interfering RNA with Functional Peptides Containing Sericin-Based Hydrogel for Atopic Dermatitis

The small interfering RNA (siRNA) is suggested to offer a novel means of treating atopic dermatitis (AD) because it allows the specific silencing of genes related to AD pathogenesis. In our previous study, we found that siRNA targeted against RelA, an important nuclear factor-kappa B (NF-κB) subdomain, with functional peptides, showed therapeutic effects in a mouse model of AD. In the present study, to develop a topical skin application against AD, we prepared a hydrogel containing anti-RelA siRNA and functional peptides and determined the intradermal permeation and the anti-AD effects in an AD mouse model. We selected the silk protein, sericin (SC), which is a versatile biocompatible biomaterial to prepare hydrogel as an aqueous gel base. We found that the siRNA was more widely delivered to the site of application in AD-induced ear skin of mice after topical application via the hydrogel containing functional peptides than via the preparation without functional peptides. In addition, the ear thickness and clinical skin severity of the AD-induced mice treated with hydrogel containing anti-RelA siRNA with functional peptides improved more than that of mice treated with the preparation formulated with negative siRNA.

Wound healing in urology

Wound healing is a dynamic and complex phenomenon of replacing devitalized tissues in the body. Urethral healing takes place in four phases namely inflammation, proliferation, maturation and remodelling, similar to dermal healing. However, the duration of each phase of wound healing in urology is extended for a longer period when compared to that of dermatology. An ideal wound dressing material removes exudate, creates a moist environment, offers protection from foreign substances and promotes tissue regeneration. A single wound dressing material shall not be sufficient to treat all kinds of wounds as each wound is distinct. This review includes the recent attempts to explore the hidden potential of growth factors, stem cells, siRNA, miRNA and drugs for promoting wound healing in urology. The review also discusses the different technologies used in hospitals to treat wounds in urology, which make use of innovative biomaterials synthesised in regenerative medicines like hydrogels, hydrocolloids, foams, films etc., incorporated with growth factors, drug molecules or nanoparticles. These include surgical zippers, laser tissue welding, negative pressure wound therapy, and hyperbaric oxygen treatment.